diff -r cda93720c06d Lib/unittest/test/test_break.py
--- a/Lib/unittest/test/test_break.py	Sat Jul 23 18:15:43 2011 +0200
+++ b/Lib/unittest/test/test_break.py	Sun Jul 24 14:23:32 2011 +0200
@@ -10,8 +10,6 @@
 
 @unittest.skipUnless(hasattr(os, 'kill'), "Test requires os.kill")
 @unittest.skipIf(sys.platform =="win32", "Test cannot run on Windows")
-@unittest.skipIf(sys.platform == 'freebsd6', "Test kills regrtest on freebsd6 "
-    "if threads have been used")
 class TestBreak(unittest.TestCase):
 
     def setUp(self):
@@ -29,8 +27,15 @@
         self.assertNotEqual(signal.getsignal(signal.SIGINT), default_handler)
 
         try:
+            # When a process sends a signal to itself, POSIX states that the
+            # signal must be delivered before the kill() syscall returns. Some
+            # operating systems are known to delay signal delivery in this
+            # situation (see issues #12625, #8263 and #12469): to force the
+            # signal's delivery, we make a dummy getpid() syscall (signals are
+            # typically delivered when the process returns to user-space).
             pid = os.getpid()
             os.kill(pid, signal.SIGINT)
+            os.getpid()
         except KeyboardInterrupt:
             self.fail("KeyboardInterrupt not handled")
 
@@ -61,6 +66,7 @@
         def test(result):
             pid = os.getpid()
             os.kill(pid, signal.SIGINT)
+            os.getpid()
             result.breakCaught = True
             self.assertTrue(result.shouldStop)
 
@@ -79,9 +85,11 @@
         def test(result):
             pid = os.getpid()
             os.kill(pid, signal.SIGINT)
+            os.getpid()
             result.breakCaught = True
             self.assertTrue(result.shouldStop)
             os.kill(pid, signal.SIGINT)
+            os.getpid()
             self.fail("Second KeyboardInterrupt not raised")
 
         try:
@@ -109,6 +117,7 @@
         def test(result):
             pid = os.getpid()
             os.kill(pid, signal.SIGINT)
+            os.getpid()
 
         try:
             test(result)
@@ -134,6 +143,7 @@
         try:
             pid = os.getpid()
             os.kill(pid, signal.SIGINT)
+            os.getpid()
         except KeyboardInterrupt:
             pass
         else:
@@ -173,6 +183,7 @@
         try:
             pid = os.getpid()
             os.kill(pid, signal.SIGINT)
+            os.getpid()
         except KeyboardInterrupt:
             pass